The safety glass is obtained by interposing a thermoplastic film, preferably of polyvinyl butyral, between two glass sheets and by applying afterwards a lamination process film. The core of this safety glass has never before been colored or decorated because the polyvinyl butyral film, due to its tackiness and stickness, cannot be subjected to an impression process. Thus, the film has always been transparent or translucent so as to give the safety glass its own characteristic, consequently said glass has never been decorated and/or colored before.
Some attempts has been made to color or decorate this type of laminated glass by using a silk screening or photographic process directly to the interior surface of one of the glass plates or on the polyvinyl butyral film. When the decoration is applied to the interior surface of one of the glass sheets, the finished laminated glass becomes translucent due to the fact that the colouring material does not permeate the thickness of the plastic film but it only forms a layer between the film and the sheet of glass surface. Serious difficulties have been found when attempts has been made to decorate the film of polyvinyl butyral. In fact it is very difficult to work on this film because of its adhesive consistency due to the temperature of the enviroment and also because of its great plasticity which makes the process a very expensive and inefficient one due to the fact that said material will not resist scratching of ink deposited thereon by silk-screening process. This is the reason why such techniques for providing decorated polyvinyl butyral adhesive lamina are unsuccessful for all practical purposes.